The fontglide program reads text from a subprocess and puts it on the screen using large characters that glide in from the edges, assemble, then disperse. Alternately, it can simply scroll whole sentences from right to left.

The command to run to generate the text to display. This option may be any string acceptable to /bin/sh. The program will be run at the end of a pipe, and any words that it prints to stdout will end up on the window. (Whitespace and line breaks are ignored.) If the program exits, it will be launched again after we have processed all the text it produced. Default: xscreensaver-text(1).